Method and device for driving liquid crystal panel using dot inversion system

Abstract

Provided is a liquid crystal panel driving method and device employing a dot inversion system. The liquid crystal panel driving method includes the steps of: (a) generating an alternating signal; (b) adding a signal of a different potential to the alternating signal, to then be applied to input ends of a gamma voltage generating unit ( 72 ) and a common voltage generating unit ( 73 ); (c) applying an alternating common voltage generated from the common voltage generating unit ( 73 ) to a common electrode ( 220 ); and (d) generating the data voltage whose polarity is inverted in the gamma voltage generating unit ( 72 ) on the basis of the alternating common voltage generated by the common voltage generating unit ( 73 ). In the dot inversion system, a common voltage is formed to alternate and a data voltage is inverted on the basis of the alternating common voltage, to thereby provide an effect of performing touch detection by using the alternating common voltage in a high-definitive liquid crystal display device (LCD).

The invention claimed is: 
     
       1. A method of driving a liquid crystal panel by using a dot inversion system in which a data voltage is inverted on the basis of a common voltage, the liquid crystal panel driving method comprising the steps of:
 (a) generating an alternating signal; 
 (b) adding a signal of a different potential to the alternating signal, to then be applied to input ends of a gamma voltage generating unit ( 72 ) and a common voltage generating unit ( 73 ); 
 (c) applying an alternating common voltage generated from the common voltage generating unit ( 73 ) to a common electrode ( 220 ); and 
 (d) generating the data voltage whose polarity is inverted in the gamma voltage generating unit ( 72 ) on the basis of the alternating common voltage generated by the common voltage generating unit ( 73 ). 
 
     
     
       2. The liquid crystal panel driving method of  claim 1 , wherein the phase of the alternating common voltage is inverted for each of gate lines. 
     
     
       3. The liquid crystal panel driving method of  claim 2 , wherein the data voltage is inverted for each dot on the basis of the alternating common voltage. 
     
     
       4. The liquid crystal panel driving method of  claim 1 , wherein the alternating signal is an alternating square wave. 
     
     
       5. The liquid crystal panel driving method of  claim 4 , wherein the alternating signal alternates both in a positive direction and a negative direction. 
     
     
       6. A device for driving a liquid crystal panel by using a dot inversion system in which a data voltage is inverted on the basis of a common voltage, the liquid crystal panel driving device comprising:
 an alternating signal generating unit generating an alternating signal; 
 an alternating signal adding unit adding a signal of a different potential to the alternating signal; 
 a common voltage generating unit ( 73 ) that receives the alternating signal from the alternating signal adding unit, generates an alternating common voltage, and applies the generated alternating common voltage to common electrode ( 220 ); and 
 a gamma voltage generating unit ( 72 ) that receives the alternating signal from the alternating signal adding unit, and generates the data voltage whose polarity is inverted on the basis of the alternating common voltage generated by the common voltage generating unit ( 73 ). 
 
     
     
       7. The liquid crystal panel driving device according to  claim 6 , wherein the alternating signal generating unit is an alternating waveform generating unit ( 70 ) that generates an alternating square wave. 
     
     
       8. The liquid crystal panel driving device according to  claim 7 , wherein the alternating signal adding unit comprises:
 a first adder ( 71   a ) that adds an output signal of the alternating waveform generating unit ( 70 ) and a Vdd signal to then be applied to one end of the gamma voltage generating unit ( 72 ); and 
 a second adder ( 71   b ) that adds the output signal of the alternating waveform generating unit ( 70 ) and a Gnd signal to then be applied to the other end of the gamma voltage generating unit ( 72 ). 
 
     
     
       9. The liquid crystal panel driving device according to  claim 6 , wherein the phase of the alternating common voltage is inverted for each of gate lines. 
     
     
       10. The liquid crystal panel driving device according to  claim 9 , wherein the data voltage is inverted for each dot on the basis of the alternating common voltage. 
     
     
       11. The liquid crystal panel driving device according to  claim 10 , wherein the alternating signal alternates both in a positive direction and a negative direction.